Airplane floors typically consist of honeycomb stiffened sandwich floor panels fastened to a floor structure called seat tracks. During operation of an airplane, the floor panels accommodate a variety of forces, or loads, from sources such as air pressure differences, people walking on the floor, or horizontal movement of people sitting in attached seats due to acceleration and deceleration of the plane. One function of floor panels is to transfer these loads into a body of the airplane.
A typical fastening system used for attaching the floor panels to the seat track may include a collet body having at least two fingers and a flared head, used to fasten two objects with circular apertures together, held between ends of the fingers and the head. A sleeve insert is secured in an aperture of a first object and the collet is inserted through the sleeve insert and an aperture of a second object. A screw is used to radially expand the fingers of the collet body. The fingers each include a protruding portion that engages the second object, while the head engages the first object, through the sleeve insert.
Quality control procedures have been developed to identify and correct problems that may occur when using current technology. For example, it has been found that edges of collet fingers and screw threads may be sharp enough to trim small bits of material from one another, resulting in undesirable debris. Also, it has been found that the protruding portion of a finger may sometimes expand into a gap between the flange and the seat track, rather than below the seat track as intended, which is corrected by removing and reinstalling the fastener. Cork tape is often applied to a bottom face sheet of the floor panel, surrounding a flange of each sleeve insert to dissipate forces across the floor panel and eliminate gaps between the floor panel bottom face sheet and the seat track.